The present invention relates to a bus bar device for electrically connecting a plurality of coils provided in a motor, a stator including the bus bar device, a motor including the bus bar device, and a method for manufacturing a stator including the bus bar device.
There is a conventional brushless motor including a bus bar device having a plurality of bus bars for electrically connecting a plurality of coils arranged in a circumferential direction and supplying current from an external power supply to the coils. Japanese Patent No. 3430839 describes an example of a bus bar device including a plurality of bus bars held by an annular bus bar holder. Each of the bus bars has an arcuate shape and is formed from a linear coated conductive wire covered by an insulative coating. A connection wire is formed on each of the two ends of each bus bar. The connection wire extends in a radial direction of the bus bar device and projects radially outward from the bus bar holder. The bus bar device is arranged on one axial end of a stator core around which the plurality of coils is wound. The connection wires and ends of the coils are arranged in parallel radially outward from the bus bar holder. Then, connection terminals are mounted on the connection wires and the ends of the coils that are arranged in parallel to one another so as to surround the peripheries of the connection wires and the ends of the coils. The connection wires and the ends of coils are electrically connected to one another by swaging the connection terminals, the connection wires and the ends of the coils.
In the bus bar device described in Japanese Patent No. 3430839, the bus bars are formed from linear coated conductive wires. Hence, scrap materials are less prone to be generated and yield is high. However, the connection wires extend radially outward from the arcuate bus bars, and project radially outward of the bus bar holder. This has resulted in a problem in which the bus bar device is increased in size in the radial direction. Accordingly, it is difficult to reduce the size of the motor, which includes the bus bar device, in the radial direction.